Anti-vaccine liberal crazies.
They aren't all liberals. I've run into several right here on Free Republic.
They've all memorized the same anti-vax propaganda. And when I call them out on it, when I tell them how to fact-check for themselves, they get VERY upset.
One woman even tried to deny that her concern was about autism. She claimed that she KNOWS vaccines don't cause autism, but she won't vaccinate her kids because of the OTHER brain damage that vaccines cause.
Ironically, measles and many of the other vaccine-preventable diseases *do* cause neurological damage. But the idiots who fall for anti-vax propaganda would rather endanger their kids' health and lives in favor of being pseudo-afraid of some bogeyman. Somehow, the real dangers don't concern them as much as the pretend risks.